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Classification and Analysis of Touch LCD for Mobile Phone

2022-11-12

As we all know, the basic structure of TFT-LCD is: double glass plate+liquid crystal, with driver board and backlight, but without marker board, decoder board, tuner and other devices (such as touch screen), and does not have the specificity of a certain instrument or equipment.

手机用触摸液晶显示屏.png

The classification of each type of inspection application status should be clear about the idea of classification, and will not be summarized one by one. However, for the touch LCD screen (the touch LCD screen referred to below refers to the structure of adding a touch screen to the basic LCD structure), the author actually has some thoughts, which can be referred to below.
First of all, the original idea, including touch devices, will be classified by parts, special parts belong to special parts, and general parts belong to 8548. The original idea is that there is no major problem. Because of technical reasons, earlier touch screens were all externally attached, that is, LCD screens and touch screens were manufactured separately and then bonded together (as shown in the following figure). Under this technical background, the functions of LCD are superior to LCD, which is reasonable in the author's opinion.


微信截图_20201030151439.png


Therefore, under this technical background, how to judge the specificity has become the most critical point. Take the mobile phone as an example. Usually, it is equipped with a cover plate, a special shape, chamfering and edge removal, a reserved handset hole, a reserved microphone hole, a printed mobile phone function key, and so on. It can be seen at a glance that this is a special LCD for mobile phones.

微信截图_20201030151509.png

After watching the plug-in type, the following embedded type, which is divided into cell and oncell (cell, cell, box), can be directly visualized by looking at the picture (it is obvious that the touch layer is embedded inside the LCD screen, just saying that one is between the LCD and the glass, and the other is between the glass and the polarizer):

微信截图_20201030151551.png

In fact, this technology is not available today (It can be expanded to say the characteristics of this embedded touch screen. We should not think that this is also a layer of touch coating. The photosensitive type is not. The photosensitive type is to use semiconductor technology to manufacture some semiconductor photosensitive elements internally. After the finger touches the glass screen, it blocks the optical fiber and outputs the changing current signal, so that the finger coordinates can be calculated through the numerical control IC and then to the cpu), I don't know whether you have noticed the following two guidelines: the presentation results of these two guidelines give us another basis to judge the specificity, that is, not only from the appearance, but also for reference if there are some special features of technical indicators. However, due to the tax difference, in actual operation, we suggest that you should fully analogy the above description, not expand, and not be afraid. There is also a detail in it, that is, the big plate is not cut, but only marked on the surface, that is, the customs that needs to be processed again after import is also considered as special parts.
There are many foreshadowings, but what the author wants to express most is that under the current technical background, in fact, today's embedded touch LCD screen is the progress of the original LCD technology, which is the technical progress of integrating touch function technology into the basic LCD manufacturing process. For LCD manufacturers, this is an indispensable process step in the production of embedded LCD screen, which is essentially a LCD screen, It is just equivalent to that the LCD screen is attached with the touch function. It is reasonable to think that this embedded touch LCD screen can be clearly regarded as an LCD, which can be classified under 9013.8 under the condition that it does not have a decoding board, a marking plate, a high-frequency head, and is universal. Of course, this is just a personal opinion. I wonder if Guiyou has this idea.
The attachment is the brief introduction that the author outlined in the previous study of LCD manufacturing. If necessary, you can have a look.
There are many foreshadowings, but what the author wants to express most is that under the current technical background, in fact, today's embedded touch LCD is the progress of the original LCD technology, which is the technical progress of integrating touch function technology into the basic LCD manufacturing process. For LCD manufacturers, this is an indispensable process step in the production of embedded LCD, which is essentially LCD, It is just equivalent to that the LCD screen is attached with the touch function. It is reasonable to think that this embedded touch LCD screen can be clearly regarded as an LCD, which can be classified under 9013.8 under the condition of no decoding board, marking plate, high frequency head, and universality, just like the scope of integrated circuits adjusted by the Tariff Commission in 2017. Of course, this is just a personal opinion. I wonder if Guiyou have this idea.
The attachment is the brief introduction that the author outlined in the previous study of LCD manufacturing. If necessary, you can have a look.

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